Switch mechanism



June 10, 1958 J. WENDLING Y 2,838,623

SWITCH MECHANISM Filed Oct. 51, 1958 INVENTOR. Jaw/v Wswm ma.

SWITCH MECHANISM John Wendling, Fort Wayne, Ind., assignor to The Magnavox Company, Fort Wayne, Ind., a corporation Application October 31, 1956, Serial No. 619,440

10 Claims. (Cl. 200-11) This invention relates generally to electrical switches, and more partictularly to a rotary multiple position wafer switch.

In electronic equipment there are applications requiring rotary electrical switches in which all of the switch positions within a 360 arc of rotation must be utilized. it is also desirable in such switches to provide a mechanical stop which determines the starting and stopping position of the switch rotor. For example, such a reference point as a stop is required when the switch must be operated in the dark under such conditions that it is necessary to locate a switch position by counting contact points from the stop position.

in accordance with conventional switch structure it is not possible to provide a mechanical stop and at the same time rotate the switch to all of the switch positions. This is due to the fact that the stop itself and the contact arm subtend an arc of suificient length to prevent the switch arm from moving into a position over the last switch contact. For example, in a sixteen contact switch where the contacts are spaced at equal intervals around the circumference of the supporting structure, a conventional stop mechanism would prevent movement of the switch arm into position to engage the sixteenth contact. Thus only fifteen switch contacts could be utilized.

Electrical switches having conventional stop devices also do not permit rotation of the switch arm through a full 360 from the first contact through all of the switch contact positions and back to the first contact. Therefore, it is necessary to rotate the switch arm, of conventional switches, in a reverse direction from the last contact through all of the intermediate contact positions when it is desired to operate the switch from the last contact to the first contact.

Accordingly, the principal object of this invention is to provide a rotary electrical switch of the multiple position type wherein contacts may be disposed at evenly spaced intervals in a 360 arc and a stop mechanism may be provided which will permit use of all of the contacts when the switch arm is rotated in either direction.

Another object of this invention is to provide a rotary electrical switch of the multiple position type having a floating stop mechanism capable of providing a positive stop position and permitting a full 360 of rotation in either a clockwise direction or a counterclockwise direction.

Still another object of this invention is to provide a rotary electrical switch of the multiple position type having a floating. stop mechanism which permits more than 360 of rotation in either a clockwise direction or a counterclockwise direction so that the switch arm may be rotated from the last contact to the first or second contact without reversing the direction of rotation of the switch arm.

in accordance with this invention, there is provided a rotary electrical switch having an indexing plate or a mounting plate, a shaft mounted therein for rotatably supporting a plurality of switching wafers, a floating nited States Patent v position illustrated in full lines in Fig. 1.

stop mounted on said plate for movement through an arcuate path, and an index spring fixed to said shaft and rotatable therewith and including a finger engageable with said floating stop for determining 360 rotation of said shaft.

The above mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. l is a top plan view of the switch provided in accordance with this invention.

Fig. 2 is a front elevation of the switch illustrated in Fig. 1.

Referring to the drawings, this invention comprises a rotary electrical switch having an indexing or mounting plate 10 in which there is fixed a threaded bushing 11 adapted rotatably to support a shaft 12 having an operating knob 14.

A number of contact supporting annuli 15 my be supported from the plate 10 by means of the bolts 16 and cylindrical spacer members 17. The annuli 15 are provided with stationary wiper contacts such, for example, as 18 which cooperate with contact making and breaking discs or wafers 19. A plurality of evenly spaced contacts (not shown) may be supported around the periphery of each wafer 19.

The plate 10 is formed to provide a peripheral notch at 20, for example, and cooperating therewith is a pivoted lever 21 mounted on plate 10 by means of a suitable shoulder stud 22. Lever 21 is provided with a turned over end or stop 23 which projects into the slot 20, whereby the angular movement of lever 21 is limited by the end wall of slot 20.

An indexing spring 25 may be secured to shaft 12 by means of a plate 26 having a frictional fit with respect to shaft 12 and having a central aperture formed to fit the flat sides 27 of shaft 12. Spring 25 may be secured to plate 26 by means of the rivet 28. Spring 25 includes a finger portion 29 projecting into the way of the stop 23 of lever 21. For indexing the movement of shaft 12 and the wafers 19, the plate 10 may include slots 30 which receive the ball 31. The spring 25 may be provided with a ball confining aperture 32 so that the ball will move from one notch 30 to another as the shaft 12 is rotated.

In order to provide 360 movement of the switch, the notch 20 is dimensioned to be approximately three times the width of the outer end of lever 21 or the finger 29 of spring 25. The outer end of lever 21 is approximately equal to the width of finger 29. Therefore, the shaft 12 and spring 25 may be rotated in a clockwise direction until finger 29 is stopped by lever 21 in the Alternatively, the shaft 12 may be rotated in a counterclockwise direction until finger 29 reaches a position in engagement with lever 21 in the dotted line position illustrated in Fig. 1. It will be apparent that finger 29 moves into the identical position after clockwise or counterclockwise rotation of the shaft 12, thereby permitting shaft 12 to rotate a full 360 in either clockwise or counterclockwise direction of rotation.

From the foregoing description it will be apparent that this invention provides a stop mechanism for rotary switches which permits use of all of the available contact positions. For example, it may be assumed that each of the slots 30 represent a contact position whereby there are twenty-four evenly spaced contacts on the switch. The conventional stop mechanism would prevent lever 21 from rotating into such a position that the twenty-fourth contact could be utilized. This invention makes it possible to use all contact positions. This invention also makes it possible to operate the switch through a full arc of 360 from its No. 1 position through all intermediate positions and again to the No. 1 position. Thus it is possible to move the switch arm from itslast position to its first position without reversing the direction of rotation.

It is withinthe scope of this invention to provide rotation of the switch only into the twenty-four contact positions or to provide more than 360 rotation of the switch. For example, the notch 20 may be dimensioned to be approximately four or five times the width of the outer end of lever 21 and the'finger 29. In a twentyfour-position switch, such as that shown in the drawing, it would be possible to continue rotation from position twenty-four, for example, through positions one and two without reverse rotation of the switch. While the drawings illustrate a notch in the periphery of plate 10, the end walls of which serve as stop surfaces for lever 21, it will be obvious to those skilled in the art that other forms of stop surfaces may be provided, such, for example, as lugs projecting upwardly or downwardly from the plate 1%.

The invention claimed is:

l. A switch mechanism comprising an indexing plate having a peripheral notch formed therein, a shaft rotatably mounted in said plate, switch-control elements mounted on said shaft for rotation thereby, a plate mounted on said shaft to rotate therewith and including a finger end portion extending radially of said plate into register withsaid notch, and a lever pivotally mounted on said indexing plate and including a stop disposed within said notch in the path of movement of said finger, said stop being movable back and forth between the end walls of said notch to stop said finger and shaft in a predetermined position regardless of direction of shaft rotation.

2. A switch mechanism comprising a plate having a peripheral notch formed therein, a shaft rotatably mounted in said plate, switch-control elements mounted on said shaft for rotation thereby, a finger mounted on said shaft to rotate therewith and extending radially of said plate into register with said notch, and .a movable stop mounted on saidindexing plate and including a portion disposed within said notch in the path of movement of said finger, said stop being movable back and forth between the end walls of said notch to stop said finger and shaft in a predetermined position regardless of direction of shaft rotation.

3. A switch mechanism comprising a stationary plate having a notch formed in an edge thereof, a shaft rotatably mounted with respect to said plate, switch control elements mounted on said shaft for rotation thereby, a finger mounted for rotation by said shaft and extending radially of said plate into register with said notch, and a lever pivotally mounted on said stationary plate and including a stop disposed within said notch in the path of movement of said finger, said stop being movable back and forth between the end walls of said notch to stop said finger and shaft in a predetermined position regardless of direction of shaft rotation.

4. A switch mechanism comprising a stationary plate having a notch formed in an edge thereof, a shaft rotatably mounted with respectto said plate, switch elements mounted on said shaft for rotation thereby, a finger mounted for rotation by said shaft and extending into register with said notch, and a movable stop mounted on said stationary plate and including a portion disposed within said notch in the path of movement of said finger, said stop being movable back and forth between the end walls of said notch to stop said finger and shaft '4 in a predetermined position regardless of direction of shaft rotation.

5. A switch mechanism comprising a stationary plate having arcuately spaced stop surfaces operatively associated therewith, a shaft rotatably mounted with respect to said plate, switch-control elements mounted on said shaft for rotation thereby, a finger mounted for rotation by said shaft and extending radially of said plate, and a lever pivotally mounted on said stationary plate and including a portion disposed between said stop surfaces and in the path of movement of said finger, said stop being movable back and forth between said stop'surfaces to stop said finger and shaft when said stop engages either one of said stop surfaces.

6. A switch mechanism comprising a stationary plate having arcuately spaced stop surfaces operatively associated therewith, a shaft rotatably mounted with respect to said plate, switch elements mounted on said shaft for rotation thereby, a finger mounted for rotation by said shaft and extending outwardly thereof, and a movable stop mounted on said stationary plate and including a portion movable into engagement with either of said stop surfaces and disposed in the path of movement of said finger, said stop being movable back and forth between said stop surfaces for stopping rotation of said shaft after movement of said movable stop through a predetermined arc.

7. A switch mechanism comprising a stationary member, a shaft rotatably mounted in said member, switch control elements including a finger mounted for rotation by said shaft, and a movable stop mechanism operatively connected between said finger and said stationary member for stopping said shaft in a predetermined position regardless of direction of shaft rotation.

8. A switch mechanism comprising a stationary member, a shaft rotatably mounted on said member, a switch wafer fixed to said shaft and bearing a plurality of contacts equally spaced from one another about the axis of said shaft, a stationary contact mounted on said member to engage said wafer contacts, a finger fixed to said shaft for rotation therewith, and a stop mechanism mounted on said member in the way of movement of said finger and movable through a distance at least equal to the width of said finger to permit movement of said wafer through all contact making positions.

9. A switch mechanism comprising a stationary member, a shaft rotatably mounted on said member, a switch mechanism mounted on said member and said shaft and including a plurality of contacts equally spaced from one another about the axis of said shaft, a finger fixed to said shaft for rotation therewith, and a stop mechanism mounted on said member in the way of movement of said finger and movable through a distance at least equal to the width of said finger to permit movement of said switch mechanism through all contact making positions.

10. A switch mechanism comprising a stationary member, a shaft rotatably mounted on said member, a switch mechanism mounted on said member and said shaft and including a plurality of contacts equally spaced from one another about the axis of said shaft, a finger fixed to said shaft for rotation therewith, and a stop mechanism mounted on said member in the way of movement of said finger and movable through a distance sufiicient to permit movement of said switch mechanism through all contact making positions.

References Cited in the file of this patent UNITED STATES PATENTS 1,402,696 Wallis Ian. 3, 1922 

